I think the different listing is a good idea for other reasons.
What if someone is looking for those special games that have the nifty DSi stuff? They'll have a lot of trouble going through all of the 4000 or so DS games for that one game that lets them take pictures of themselves.

As for the serial number thing, even if it does sound like a safe bet, maybe a simple warning in the nfo file by the dumpers would do the trick. They HAVE to have the game before dumping it anyways.